chronon

For those of you following my saga, I have a 2001 TT under CPO warranty that is eating 1qt/oil every ~450mi which has been documented by the dealer. Now that the claim was submitted to PCNA and they tested the car the found fouled oily sparkplugs but compression and leakdown tests were fine. Therefore PCNA is saying that likely problem is faulty oil gauge and that therefore oil may have been overfilled which may have fouled the plugs. Doesn't sound right to me but can someone explain me what happens to the oil when it is overfilled - any chance it can foul the plugs?

Ryan C

Well, the engine is dry sump so that means there is a separate reservior for the oil. The reservior has to be ventilated to the PCV(positive crankcase ventialtion) system. So there's air in there that eventually ends of in the engine. If the oil was overfilled you could end up having oil go through that hose for air and put oil straight into the intake manifold and into the combustion chamber from there. That might be why they see oil on the spark plugs.

Ryan C

So I found and read your other thread about this. Does the car smoke on start up? I'm sursprised to see that no one has questioned the turbos them selves. If it doesn't smoke on start up then it's not the turbos. I'm also not saying that smoke at start up equals bad turbo's but it could be a lead. There are check valves to hold oil pressure from settling in the turbo's when you turn the car off. If these are bad the turbo can fill with oil and it will burn and get blown through the intake system.

chronon

There is no smoke at start-up and in fact the dealer has indicated that their mechanic believes that there is an internal issue with the engine. But Porsche doesn't seem convinced despite having done all the oil consumption tests as per dealer instructions. (all documented with pics as well - oil going down 1 bar every ~120 miles). That's were the argument on the oil gauge being the issue seems bogus to me.

k4site

If you are runing under boost alot you will use more oil and nonboost condidtions. If after the engine warms up at idle you experience white smoke you my have leaking seals.